Process for converting cyannaphthalene-sulphonic acids



' Patented July 1928.

um-ED STATES PATE T OFFICE.

RICHARD HERZ AND FRITZ :SCIIULTE, OF FRANKFORT-ON-THEMAIN, AND WERNER ZERWECK, OF FECHENHEIM, NEAR FRANKFURT-ON-THE-MAIN, GERMANY, AS- SIGNORS TO GRASSELLI DYESTUFE CORPORATION, OF NEW YORK, N. Y., A CORPO- RATION OF DELAWARE.

PROCESS FOR CONVERTING CYANNAPHTHALENE-SULPHONIC ACIDS.

No Drawing. gr iginal application filed iebruary 24,1927, Serial No. 170,732, and in Germany December '4," 1925. Divided and this application filed November 10, 1927. Serial No. 232,467.

This application is a division of our application Serial No. 170,732, filed February 24th, 1927. y

We have found, that if cyannaphthalenesulphonic acids, containing at least one sulphonic group in orthoor paraposition tothe I cyanic group, are treated with an alkaline acting agent at elevated temperaturesfthis sulphonic group, standing in ortho or para position to the cyanic group, is easily exchanged to other monovalent radicleis.

The products of 4 conversion, thus obtained correspond to the general formula:

in which'formula the group OY stands iri ortho or para position to the group Z, the Xs mean hydrogen atoms, vof which one or more may be replaced'by a -monovalent substituent, Y means hydrogen or an allgll residue, Z the groups ON, CONH and OOH.-

The general formula shows the range of substances, obtained according to'th'e conditions applied. By acting with milder acting alkaline agents, the cyangrofip of the cyannaphthalenesulphonic acids employed remainsunattacked and hydroxy-cyannaph- 0 ing to the above formula,-Y being hydrogen and Z being ON. By acting with stronger alkaline acting agents the cyangrou is saponified to the carboxyamido; (Z=- ONH," in this case) or to the carboxy-group (Z= COOH in this case) whereas the su phonic group is exchanged by hydroxyl (OH), when the applied alkaline acting agent is an aqueous caustic alkali, or by an alkoxy group, generally when applying caustic alkalis in I presence of an alcohol, This latter reaction by-which an alkoxy group is introduced in the molecule, is a particularly remarkable onewithout any analogy inthe naphthalene series. In this manner especially alkoxynaphthalenecarboxyamids corres onding to the above formula,Z being GO H and Y'being an alkylresidue, and hydroxyand alkoxy-naphthoic acids are obtained corresponding to the above formula, Z' being thalene-compounds are formed correspond- COOH and Y being hydrogen or an alkylresidue.

Under the term alkaline acting agents we understand caustic alkalies in presence of water or of an alcohol, acting either at ordinary pressure or in a closed vessel at ele- Under milder acting alkavated pressure. line agents the following have been found especially suitable; basic alkaline salts such as sodium-formats, acetate, borate, phosphate. Such agents, the caustic alkalis as well as the milder acting agents may be used advantageously in presence of inorganic or organic diluents in order to keepthe mass homogeneous and easily liquid, such as parafiine, naphthalene, tertiary aromatic bases as dimethylaniline or N-alkyl-carbozol, higher fatty acids, glycerineor low melting salts. r

The aforesaid reactions take place at remarkable low temperatures, namely at about 250 C., Whereas Boyle and Shedler and Butler and Royle (see J ourn. of Chem. Soc. London,'vol. 123, pages 1641, 1649) must apply temperatures above 260 to 800 for exchanging the sulphonic group by the hy-- droxylgroup in' the corresponding cal-boxynaphthalene-sulphuric acids.

The starting materials for these reactions, namely the orthoand para-cyannaphthalenesulphonic acids and their nuclear substitution product's, particularlythose, con

taining a halogen or a further sulphonic group in the nucleus-are obtainable by diazotizi-n the corresponding aminonaphthalenesulp ionic acids and treating the diazocompounds, thus obtained, with cuprous cyanide according .to Sandmeyers reaction.

'All products of conversion, derived therefrom, are important intermediates for the production of dyestuffs and pharmaceutical products I In order to further illustrate our invention the following examples are given.

. Example 1. "v 40 parts of caustic potash and 40 parts of of the sodium salt of:-1-cyannaphthalene-2- sulphonic acid obtained from the l-amino- 2-naphthalenesu phonic acid, see Liebigs Annalen, vol. 388, page 7) are added whilestirring. The temperature of the mass is slowly increased to about 130140 C. and

I the mass is kept'at this temperature for a short time, until a test, when acidified, shows that the formation of a compound,'insoluble thus obtained forms long colorless needles,

melting at 189, as described in literature. It has been formerly prepared by Gattermann (cf. Liebigs Annalen, vol. 244, page of the mass is increased to about IOU-120 of alkali .washed with water.

) in a complicated manner, unfit for technical purposes, by reacting with urea-chloride. and aluminiumchloride on B-naphthoL ether.

When using caustic ethylic or butylic alcohol in this process the corresponding ethoxyand butyloxy-compounds are obtained. a

- Ewample 2.

. 40 parts of caustic potash and 25 parts of methylic alcohol are heated for some time at about At this temperature 10 parts of the sodium salt of Q-cyannaphthalene-l-sulphonic acid are added. The temperature and the mass is kept for a short time at this temperature, until a test as describedin the foregoing example shows the formation of a compoundv insoluble in dilute solutions metal carbonates. Then it isv cooled down and diluted 'with' water,

Thereby a precipitate is separated, which is insoluble in alkalies. It is filtered and The new compound, being probably the 1-methoxynaphthalene-2-carboxyamide of the formula CONH:

crystallizes from water or dilute alcohol as long colorless needles, melting at 156157.

By saponiiying the new compound with alkaline acting agents, for instance by heating it with a dilute caustic soda solution,

preferably with addition of alcohol, until the evolution of ammonia ceases, it is converted into the corresponding. l-methoxynaphthalene-2-carboxylic acid, which forms, when recrystallized from dilute Jalcohol bright needles, melting at 127,as described in literature (see Hiibner, Monatshefte'fiir Chemie, vol. 15, page 735).

-When using other aliphatic alcohols for the process the corresponding alkoxyderivatives are formed. The same reaction takes place when using benzylalcohol or also an aromatic phenol. With polyvalent alcohols such as glycol the corresponding derivatives are formed.

Example i 1 part of the sodiumsaltof l-cyannaph- -thalene-4-sulphonicacid is added at about to a mixture of 4 parts of caustic potash and 6 parts of methylic alcohol. Then the. mixture is heated under reflux for some hours until a test; as decribed inexample 1 shows, that this formation of a compound, insoluble in dilute solutions of alkali metal carbonates, is finished. After cooling down the mass is diluted With Water and the separated l-methoxy-l-naphthamide of the formula OONH:

potash in presence of is isolated by filtration. It has the properties described in literature (of. Gatter-.

mann, Liebigs Annalen, vol. 244, page 73,

who prepared it in a complicated manner,

unfit for technical purposes by reacting with ureachlorideand aluminiumchloride on a-naplhtholether) W en recrystallized from dilute alcohol it is obtainedas colorless crystals, melting at 237. It is insoluble in cold alkalies, when heated with caustic alkaline solutions it is converted into the corresponding carboxylic acid.

When in this process the temperature of reaction is increased to about (by partly distilling off the alcohol) evolution of ammonia begins; after heating the mass for some hours at this temperature until a test, when acidified, shows that the formation of a compound, easily soluble in dilutesolw tions of alkali metal carbonates, is finished, the formed 4-methoxy l-naphthoic acid of the formula coon CH3 separates by diluting the mass with wate Example 4. If instead of methylic-alcohol ethylic alcoholis used and the process is otherwise 7 carried out as described in the foregoing example, the 4-ethoxy-1-naphthamide and the 4-ethoxy-l-naphthoic acid are obtained,

literature (of. Gattermann, l. 0.). The 4- ethoxy-l-naphthamide crystallizes from dilute alcohol as colorless needles, melting at 244. It is insoluble in cold alkalies, when heated with a caustic alkaline solution the corresponding acid is formed. This 4- ethoxy-l-naphthoic-acid crystallizes from dilute'alcohol as colorless needles, melting at 214. It is easily soluble in alkalies.

Example 5. i 7 When using n-butylic alcohol instead of methylic alcohol and carrying out the re action otherwise as described in the fore going examples, at first the 4-n-butyloxy-1- naphthamide of the formula:

CONH:

lizes from spirit in silver shining needles, melting at 250. p I By increasing the temperature of the reaction the corresponding 4-n-butloxy-1- naphthoic acid of the formula:

' I coon I OHsCHzOHaCHa is obtained, being also a new compound,

crystallizing from spirit as colorless needles I duced.

Among the products of conversion, derived from orthoand para-cyannaphthalenesulphonic acids, herein described, the by droxynaphthoic-acids obtainable; according to the aforesaid reaction with an excellent yield and in a pure state are already known in the literature, whereas the hydroxycyani naphthalene-compounds obtainable as intermediates by this reaction, are new bodies.

The alkoxynaphthamides' and alk0xynaph- 'thoic-acids are new compoundswith excep- -tion of the following, which have been prepared in a complicated manner, unfitfor technical purposes, as stated above:

(1) 2-methoxy-l-naphthamide, (Liebigs Annalen, VOl. 244, page 75.)

page 7 3.)

(3) 4-methoxy-1-naplithamide, 1. c.,.

(5) 2-methoxy-1-naphthoic acid (Bulletin/3/, vol. 17, page 311.)

(6) 2-ethoXy-1-naphthoic acid, (Comptes rendus, vol. 136, page 618.)

(7) 1-methoxy-2-naphth'oic acid (Monatshefte fiir'Chemie, vol. .15, page 735.)

(8) 4-metho'xy-l-naphthoic acid, (Liebigs Annalen, vol. 244, page 73.)

7 9) 4-ethoxy-1-naphthoic acid, (1. 0., page- I in which formula the Xs mean hydrogen is obtained. The new compound crystalatoms, of which one or more may be replaced by a mono'valent substituent, and thecyanogen and at least one sulphogroupstand to products of conversion of the probable formula 0 a1ky1 CONE in which formula the alkoxygroup stands in orthoor paraposition. to the'carboxyamidogroup, and the Xs mean hydrogen atoms, of which one or more may be replaced by a 'monovalent substituent, which process comprises treating cyannaphthalene sulphonic-acids corresponding to the aforesaid formula at temperatures from about 80150 C. with a caustic alkali in presence of an alcohol until a test, when acidified, shows that the product obtained is insoluble in dilute solutions of alkali metal carbonates, but soluble in organic solvents, as ether, benzene, etc.

5()2) 2-ethoxy-1-naphthamide, (1. 0., page having the properties, described in the 73 i h -"P the following csi each other in orthoor paraposition, into which process" comprises treating the 2- cyann'aphthalene-l-sulphonic acid at temperatures from about 80 to 150 With a caustic alkali in presence of methylic alco-' 1101, until a-test, when acidified, shows that the product obtained is insoluble in dilute solutions of alkali metal carbonates, but soletc.

3. As a new compound the 1-methoxy- I naphthalene-2-carboxyamide of the probable formula tures.

CONE] being when dry a colorless powder, crystalsoluble in alkalies, which compound. is submelting at 156-157", 111- stantially identical'with a product obtainable by treating the 2-cyahnaphthalene-1 sulphonic acid at temperatures from about to with a caustic alkali in presence of methylic alcohol, until a test, when acidified, shows, that the product obtained is insoluble in dilute solutions ofalkali metal "carbonates, but soluble in organic solvents,

I 'as ether benzene etc. uble 1n organlc solvents, as ether, benzene,

In testimony whereof,

RICHARD HERZ. FRITZ SCHULTE. WERNER ZERWECK.

we aflix our signa 

